Senior Data Base Administrator

Project: HR SaaS for the public sector. We are looking for a Senior Database Engineer to execute a production database migration from on-premises Microsoft SQL Server to Amazon RDS for a large HR/Learning SaaS platform serving public-sector and government agencies. You will own the migration mechanism end-to-end: moving multiple active OLTP databases with a near-zero-downtime cutover and a verified rollback path. This is a hands-on delivery role embedded in a cross-functional team (Backend, DevOps, and the client's existing DBA and QA teams). Beyond the migration itself, you will diagnose and resolve database-layer issues that surface during parallel run and cutover (latency, connection routing, read-only replica behavior). The platform's longer-term direction includes introducing PostgreSQL alongside SQL Server, so experience with a polyglot estate is a strong plus.

Key Responsibilities:

• Execute the migration of the OLTP database from on-prem SQL Server to Amazon RDS for SQL Server (Multi-AZ)  for dependent products.
• Provision and configure RDS instances (Enterprise Edition for AG support), parameter groups, option groups, backups, and Multi-AZ HA across all environments.
• Validate RDS feature compatibility: Change Tracking (required for downstream ETL) and CLR SAFE assemblies; prepare and cost the fallback path
• Diagnose and fix database-layer issues during parallel run and cutover: Transit Gateway / cross-network latency, connection-string and read-only routing, command timeouts, and accidental writes to read replicas.
• Define and rehearse cutover and rollback runbooks (failover/failback timings, RPO/RTO targets, validation steps); support QA parity testing and performance baselining
• Establish monitoring, alerting, and backup/recovery (CloudWatch, Performance Insights, point-in-time recovery) for the migrated databases.

Tools and skills you will use in this role:

• Microsoft SQL Server (T-SQL, Always-On Availability Groups, Change Tracking, CLR)
• Amazon RDS for SQL Server (Multi-AZ), AWS DMS
• AWS (VPC/Transit Gateway, S3, CloudWatch, Performance Insights, IAM)
• Nice to have: Infrastructure-as-Code (AWS CDK)
• Nice to have: PostgreSQL / Amazon RDS / Aurora PostgreSQL

Requirements:

• 5+ years as a DBA / Database Engineer in production environments.
• Deep Microsoft SQL Server administration expertise: Always-On Availability Groups, replication, backup/restore, log shipping, Change Tracking, performance tuning, and T-SQL.
• Proven experience migrating SQL Server workloads to AWS, ideally Amazon RDS for SQL Server, including AG-based and/or DMS-based approaches.
• Strong understanding of HA/DR, RPO/RTO, cutover, and rollback planning for active production systems.
• Hands-on AWS experience: RDS, networking (VPC, Transit Gateway), S3, monitoring, IAM.
• Ability to troubleshoot database connectivity, latency, and routing issues in hybrid (on-prem + cloud) topologies.
• Experience working alongside a client-side DBA team and coordinating phased, multi-environment rollouts.
• English: Upper-Intermediate or higher.

Nice to have:

• PostgreSQL administration and SQL Server-to-PostgreSQL migration experience (schema, stored procedures, data-type mapping, dual-write/cutover).
• Familiarity with EF Core / Npgsql and .NET application data layers.
• Experience with AWS DMS for heterogeneous migrations.
• Infrastructure-as-Code with AWS CDK; CI/CD-driven database migrations.
• Exposure to regulated/compliance environments (e.g. FedRAMP).